Attaching soles to welted shoes



G. 1'. HART, JR 2,426,267,

Aug. 26, 1947:

' ATTACHING SOLE T0 WELTED SHOES 2 Sheds-Sheet 1 `m" ""n Illl//llllllllz l Invemor George Har, l. By is AttorneyV Aug. 2s, 1947.

G. T. HART, JR

TTCHING SOLE TO WELTED SHOES Filed lay 23, 1944 2 Sheets-Sheet 2 Inventor wu n l 0 A .w DMU.

Patented Aug; 26, 1947 n'iTAcnING soins4 'ro WELTED snoEs eorgel T. Bart, Jr., Lynn, Mass., assigner to f United Shoe Machinery Corporation, Flemington, N. JL, a corporation of New Jersey Application May 23,1944, Serial No. 536,857

1' :i Claims. (Cl. 12-14Z) This invention relates to methods of attaching outsoles to Welte shoes, and more particularly to\ methods of attachment by means of cement acti It is Well known that soles may be attached tof shoes by means of a cement which is activated in situ by the application thereto ofi a high-frequency electrostatic iield which producesl heat directly in the cement. Such methods have commonly been applied to shoes' of the McKay type in which the edge ofthe sole s close to the periphery of the shoe last with the inherent reL sult that the sole and shoe are iirmly held together during the activation of the' cement.v by pressure applied tothe outsole and to the last within the shoe. Thesemethods are not applicable to welted shoes, however, in which the outstanding welt strip is unsupported by the last and in which, consequently, there is no assurance that this strip will be held in engagement with the outsole during the' activation of the cement. While `those methods employing a stray eld to activate the band 'of cement in the forepart of the shoe provide many advantages, they are subject to the production of unused amounts of heat generated inthe non-cemented mid-portions including the filler.

.When attaching outsoles to such vshoes by means of a solvent-activated cement, it is the custom Ato apply pressure to the outstanding welt by means of a welt-holddown member closely surrounding at least the forepart of the shoe, and pressure is applied through this holddown member to keep the welt strip inlflrm Contact with the outsole.

One important object of the invention is to devise an improved method'of attaching outsoles to welted shoes which makes it possible to activate the cement in situ While pressure is applied to keep the welt in iirm contact with the sole.

In one aspect my invention contemplates a novel method in which" pressure is applied toy clamp together the Weltstrip, a holddown electrode extending around-at least the forepart of the shoe and with the help of which an electrostatic field is setup traversing the band of attaching cement and the-outsole, and then acti-fA vating the cement.

In another aspect, invention will `be found in 'utilizing the welt holddown both for the producthat area -While the activation of cement in the shank portion is advantageously eiected Iby means of a stray field which is' little affected by the metal of the shankpiece. `Such a method is applicable to those welted shoes invwhich the weltextension on the shank portion of the shoe is not suiiiciently great to require the application of clamping pressure tothe welt strip. l

These and other aspects of the invention Wil now be discussed in the following specification taken inr connection 1 withv the accompanying drawings, in which Fig. l is an angular view, illustrating the application of cement to an outsole; Y l

Fig. 2 is a similar view, illustrating the application of cement to a shoe bottom;

Fig. 3 is a transversevertical section through the forepart of a shoe positioned in a sole attaching machine modified for the utilization of applicants method;

Figs..4, 5 and 6 are transverse sections of the forepart of a shoe, in the bottom structure of which an electrode strip has been embodied for cooperation with a Welt-holddown electrode; and

Fig. '7 is a diagrammatic plan view of an electrode pad facilitating the application of a direct iield to the band of cement around the forepart of the shoe and of a stray iield to the shank portion of the shoe. l

In preparing the bottom of a lasted shoe S having an outstanding welt strip I2-for the attachment thereto of an outsole I4, it is common practice to apply to the attaching iace'of the welt Y strip a. band of cement I6' (Fig, 2) which ordinarily will extend over the edges of the inseam y |8. This may be applied by means of a hand brush 20 or in any other desired fashion. When thesole is to be attached by means of a thermoplastic cement lwhich may be activated in a highfrequency electrostatic iield, the cement, utilized will be of a type which may be activated in situ after the sole has been pressed against the shoe and can be one of the vinylite resin types of cement, although there are many others which are applicable. l The preparation of the shoe bottom also includes the application of shoe filler material 22 to the forepart of the shoevand frequently includes the application of a shank piece 24 which may be of fiber, wood or even metal. In

some cases, it will be found vdesirable and convenient to include'an electrode strip 26 such as of metal foil in the shoe bottom closely adjacent to the inner periphery of the inseam, and to provide a lead 21 by which it can `be 'connected to one side of an oscillator. This strip maybe held in asuitable manner as byan adhesive which needs onlyto be strong enough to hold the stripl in place until the sole is attached. A band of cement 30 will also usually be applied to the peripheral margin f the outsole I4 by means of a hand brush 32 or in any other desired Way.

After these coatings of cement have dried, they then being hard and non-tacky, thereby facilitating the correctl positioning of the outsole with respect to the shoe bottom, the shoe S and the outsole I4 will be brought together in a sole-attaching machine, such as the one illustrated in Letters Patent; of the United States No. 2,138,960, granted December 6, 1 938, upon the application of Sidney J. Finn. The pad cover 34 (Fig. 3) of such'a machine may then embody an electrode plate 36 having the general shape of and underlying the forepart of ashoe to be applied to the machine. In some cases this plate will extend the full length of a, sole- Such a plate will be of flexible metallic material and will usually be slightly smaller than the peripheral outline of the smallest sole to be applied in the machine. A wire lead 38 attached' to the plate 36, in any convenient location, will extend outwardly of the pad for a purpose to be later described. Pressure may be applied to the shoe bottom by way of the last through various members including a toe pad 40 and to the welt through a holddown member 42 extending around at least the forepart of the shoe and contacting substantially the whole width of the grain or upper surface of the welt strip I2. Frequently, such a welt holddown will be slightly flexible and usually will be of electrically non-conductive material so that an outer electrode 44 which may be in the form of a wire or cable maybe embodied directly in the welt holddown itself. If the holddown itself is conductive, then the cable will have an insulating cover. To such an electrode, a convenient lead 46 will be applied to enable its attachment to a source of supply of hig".frequency current such as an oscillator (not shown). In using this arrangement, as pressure is applied from above or below to clamp the welt firmly in contact with the outsole, a high-frequency electrostatic field will be set up between this electrode 44 and the plate 36 which will pass substantially vertically of the shoe through the band or bands of cement previously applied. The production of heat in this cement will take place rapidly, enabling the cement to be activated in situ and will not require the time necessary for the dissipation of a solvent as is the case when solvent-activated cements are employed. Owing to the shape and location of the electrodes the part of the field which extends over into the mid-portions of the forepart of the.\ sho e is much weaker than the part of the field-which passes directly throughthe band of cement, with the inherent result that the amount of heat which is generated in the mid-portion is small. This constitutes an advantage of the application of the direct field in the forepart of the shoe, as compared to the use of the fringe field in the forepart which, as it has been used in previous cases, produces unused heat in said mid-portions, although the fringe eld may have other advantages, making it desirable for certain purposes.

In some instances, it may be preferred to cause the electrostatic eld to pass horizontally through the layer of attaching cement from edge to edge thereof, and this can readily be accomplished when an electrode strip 26 has been embodied in the shoe bottom, as shown in Figs. 2 and 4. In some instances, it may be found preferable to apply a wire electrode 26' (Fig. 5) to the shoe bottom in place of the strip of foil, and such a wire electrode will usually be laid against the inner face of the inseam and held there, it may be, by the stickiness of the shoe filler material. The method of sole attaching involving the use of an electrode incorporated in the shoe bottom and extending along the inner edge of the cement I band positioned between the welt and an applied sole is claimed in a divisional application, Serial No. 731,077, filed February 26, 1947, in my name. In the use of arrangements shown in Figs. 4 and 5, the field will be understood to extend from the holddown electrode 44 to the shoe bottom electrode 26 or 26' substantially horizontally and substantially in the plane of the attaching cement. In other instances, it may be found desirable to cause the field `to be more exactly in the plane of the attaching cement, and this may readily be accomplished by supporting a similar outer electrode 44 (Fig. 6) by means of brackets 48 extending outwardly and downwardly from the welt holddown 42. It will be understood that, with this arrangement, either an inner electrode strip of foil 26 may be employed or the wire 26' shown in Fig. 5.

The design of cement shoes frequently is such that the extension of the welt in the shank portion of the shoe is considerably less than it is in the forepart of the shoe, so that it is not necessary to use a. welt holddown in this portion of the shoe bottom. When that is the case, an electrode pad such as that shown at 5l) in Fig. 7 will be substituted for the pad cover 34 of Fig. 3. Such a pad will be provided with a forepart plate 52 corresponding to the plate 36 and, vcombined with it, will have a stray-field-electrode structure 54 including interdigitated strips 56 and 58, alternating strips being interconnected and provided with outwardly extending leads 60 and 62. The strips 58 will'also be connected to the forepart plate 52 by a lead 64 which may be buried in the pad. Inasmuch as the bars 56 and 58 of the stray-eld electrode 54 extend transversely .0f a shoe bottom, the eld produced by them will be little affected by any metal in the shank piece. It will be understood that, in the use of this pad, the forepart field will be set up between a holddown electrode 44 and the plate 52, as in the arrangement shown in Fig. 3, thereby producing a direct field in this portion of the shoe while, in

' the shank portion, the stray field bulging upwardly from the pad will activate the cement bands along the sides of the shank portion of the shoe. In the use of such an electrode, the electrode member 44 will be connected to the same side of the oscillator (not shown) as is the electrode lead 60, while the lead B2 will be joined to `the other side thereof. The effectiveness of the preceding method is further enhanced by the fact that the configurations of the two types of elds in the respective portions of the shoe to which they are applied are particularly adapted to the efiicient conversion of electrical energy into heat energy confined substantially only to the cemented areas. The reason for the efficiency of the marginal direct eld in the forepart has already been stated. As to the utilization of the stray field in the shank, since the width 'of the sole of the shank is such that the band of cement extends substantially over the entire area thereof, leaving only a narrow non-cemented strip in the mid-portion, the stray eld directly encounters only a small non-cemented area into which it may pass, thus'resulting in small loss of heat.

5 Having thus described my invention, what I claim as new and desire to secure by Letters Patrtint of the United States ist 1. That improvement in methods of attaching outsoles to shoes having welt strips attached 'thereto by inseams, which consists in bringing band of cement and extending from. said insu--V 'lated holddown electrode to another electrode outside the outsole.

'outsoles to shoes having an outstanding welt strip.` which consists in securing a shank piece to the bottom of the shank portion of the shoe. applying a bottom filler to the fox-eport of the shoe bottom, Vapizalyin a coat of cement to the attaching surface of the welt strip, applying a coat of cement to the marginal portion of an outsole, bringing together said outsole and shoe after the cement has dried, applying a holddown electrode to the exposed surface of the outstanding welt, pressing the sole into contact .with the shoe bottom,clamping together the electrode. the welt and the outsole, setting up e. direct high-frequency electrostatic tleld to heat the cement in 2. That improvement in methods of attaching soles to welted shoes, which consists in bringing together an outsole and a shoe having an outstanding welt strip with a layer of cement interpositioned between the welt strip and the outsole, activating said cement by means of a direct held in the forepart of the shoe extending through the cement band around the forepart, and simultaneously activating the cement in the shank portion of the shoe by means of a stray-ed elec--v trede positioned entirely beneath the outsole.

3. That improvement in methods of attaching the Iorepart of the shoe with the aid of said holddown electrode, and setting up a stray held to heat the cement in the shank portion of the shoe.

GEORGE T. HART, Jn.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Name Date Colella Oct. 19, 1937 Ray Aug. 20,1940 Hart, Jr. Jan. '1, 1941 Crandell Nov. 2 1943 Hart, Jr Nov. 26, 194e Number 

